News Release Number: STScI-2011-04

In Deep Galaxy Surveys, Astronomers Get a Boost -- from Gravity

January 12, 2011: Astronomers are finding that the idiom "can't see the
forest for the trees" applies to the universe of
galaxies as well. In a paper published today in the
science journal Nature, an international team of
astronomers predicts that foreground galaxies will
affect images of extremely far galaxies. The
gravitational fields of the foreground galaxies distort
space like a funhouse mirror. This means that a
significant fraction of far background galaxies will
appear on the sky near foreground galaxies. The good
news is that the remote galaxies will appear brighter
because of a phenomenon called gravitational lensing.
This will need to be factored in when astronomers plan
to look for the farthest galaxies in the universe with
the planned James Webb Space Telescope.